Australian cities need to prepare for more frequent, intense and longer-lasting heatwaves, experts say, which could lead to restrictions on black roads and roofs that contribute to dangerous heat traps.

Heatwaves already kill more Australians than bushfires and cyclones and meteorologists say a looming El Nino weather system could push up summer temperatures later this year.

Scientists are investigating ways to lower the temperatures of Australian cities, including using light-coloured bitumen, planting more trees and floating the idea of banning black roofs.

“Australians regularly overestimate their ability to withstand extreme heat,” Professor Liz Hanna, an environmental health expert from the Australian National University, told Lateline.

“We think we know how to handle it because we live in a hot country but we’re now dealing with unprecedented extremes.

“We have to take heat as a health issue far more seriously.”

By 2050, an extreme heat event in Melbourne could kill more than 1,000 people in a few days unless there is better preparation, according to a Federal Government report looking at extreme heat events.